Ferrite Ceramics at Microwave Frequencies: Applications and Characterization

Abstract

This article focuses on microwave ferrites and their applications. The term ferrites designates ferrimagnetic materials, which constitute a class of magnetic materials showing high dynamic permeability and high electrical resistivity over frequencies up to several GHz. This article's aim is to present a primer to polycrystalline ferrite microwave properties, including wave propagation in magnetized ferrimagnetic materials. A special emphasis is placed on the incidence of material shape on its microwave properties. Some current applications of low-loss ferrimagnets in passive microwave components are addressed. A review of some microwave characterization methods is made in the last section.

Correlation between Low Field Microwave Power Absorption and Soft Magnetic Properties of Ferrites

“…Having a higher electrical resistivity (10 6 Ω . m), NZFO is applied in electronic devices at frequencies between 1 and 500 MHz [2].…”

“…Ferrites are a group of magnetic ceramic oxides containing the ferric ion Fe 3+ in their structure and a divalent (M 2+ ) or trivalent rare earth (R 3+ ) cation. Accordingly, to their crystal structure, ferrites can be classified as spinels (MFe 2 O 4 ), garnets (R 3 Fe 5 O 12 ), perovskites (RFeO 3 ), or as hexagonal structures related to the magnetoplumbite mineral (MOÁ6Fe 2 O 3 ) [1,2]. This diversity in composition and crystal structure provides a broad spectrum of magnetic and electrical properties which can be tuned and engineered for electronic and biomedical applications.…”

Technological Aspects of Lithium-Titanium Ferrite Synthesis by Electron-Beam Heating

“…Ferrites hold a specific place among the many technological magnetic materials. Ferrite materials, including lithium-containing ferrites, are currently the key elements in most modern radio engineering, electronic, and computing devices [ 1 , 2 , 3 , 4 ]. Lithium and substituted lithium ferrites are characterized by a sufficiently low cost, yet they exhibit a certain combination of electrical and magnetic properties, which enable their use in microwave technology.…”